1. Field of the Invention
The invention relates to a liquid crystal display device and a method of fabricating the same, and more particularly to an active matrix type liquid crystal display device and a method of fabricating the same.
2. Description of the Related Art
In a step of forming a pixel electrode and an electrode located in facing relation to the pixel electrode in a process of fabricating a liquid crystal display device, in particular, an in plane switching type liquid crystal display device, there is usually used stepper projection alignment in which a substrate on which a thin film transistor (TFT) is to be fabricated is divided into a plurality of areas, and each of areas is exposed to light in turn by means of a stepper.
In stepper projection alignment, a difference is made in a line width and registration among layers because of dispersion in a luminance of light to which divided areas of a substrate is exposed, and/or a difference in light-exposure in areas between which a stitch is located. As a result, differences in capacitance are made among electrodes formed on the TFT substrate.
Hence, it is important in stepper projection alignment to reduce non-uniformity in a luminance, caused by the differences in capacitance among electrodes formed on the TFT substrate.
In order to reduce such non uniformity, Japanese Patent Application Publication No. 2000-162639 has suggested a method of fabricating a liquid crystal display device, including a step of forming a pixel electrode and an electrode located in facing relation to the pixel electrode by stepper projection alignment, in which step, the divided areas located adjacent to each other are designed to have an area overlapping each other, and patterns in the divided areas are arranged in random number sequence in the overlapping area.
Thus, an average capacitance of a pixel electrode and an opposing electrode in the overlapping area is just a half of capacitances of the electrodes in the adjacent divided areas. This ensures that a luminance smoothly changes over the adjacent divided areas between which the overlapping area exists, and hence, image-display quality is enhanced.
However, a problem of a difference in a line width in the adjacent divided area between which an overlapping area exists is not solved in the above-mentioned conventional method. As a result, a viewer can recognize a difference in a luminance between the adjacent areas. This means that the conventional method cannot provide sufficient quality in displaying images.
Japanese Patent Application Publication No. 11-249169 has suggested a liquid crystal display device including a substrate and at least two pixels arranged on the substrate and allowing a light to pass therethrough at different transmittance.
Japanese Patent Application Publication No. 2002-182242 has suggested a method of fabricating a liquid crystal display device, including the steps of dividing at least one of an electrically conductive layer and a dielectric layer to a plurality of areas, and exposing each of the divided areas to light to pattern each of the divided areas such that adjacent divided areas have a zigzag stitch therebetween.
Japanese Patent Application Publication No. 2002-107758 has suggested a method of fabricating a liquid crystal display device, including the steps of dividing a substrate into a plurality of areas, and exposing each of the areas to light by means of a stepper such that two areas located adjacent to each other have an overlapping area which is exposed to light twice. Such an overlapping area is non-linearly formed in a sub-pixel area.
Japanese Patent Application Publication No. 2000-29053 has suggested a method of fabricating a liquid crystal display device, including the step of repeatedly using a mask for exposing each of pixel areas to light.